For more than 30 years it has supplied erotic fantasies in Peshawar, the main city of northwestern Pakistan which borders the tribal districts that are a haven for Taliban and Al-Qaeda-linked militants.
Terrified of being recognised, the Shama's customers hide their faces as they make their way to the cinema between a goat market and a bus station.
There are three X-rated shows a day in the Shama's discreet back room, while the main hall is reserved for mainstream movies -- the only ones advertised outside.
"Class X" customers pay 200 rupees ($1.90) and after a brief search by a Kalashnikov-toting guard, they are whisked through a courtyard and down a concrete passageway.
Inside the auditorium a thick cloud of cannabis smoke hangs over the 20-odd rows of tattered fake-leather seats.
During one showing, the hall was more than half full, populated by labourers, farmers, students and others who had come to escape the day-to-day claustrophobia of life in a deeply conservative Muslim region where family and neighbours keep a close eye on everything.
Most arrive alone and want to remain so, arranging themselves around the seats to avoid sitting next to anyone.
They are all soon gripped by the drama of the day's offering, Dostana
(Friendship), a semi-amateur production made for the Shama in the more liberal eastern city of Lahore.
The plot hinges on a romantic dilemma: the hero, Shah Sawar
(The Horseman - in the local language) cannot decide whether to marry his sweetheart Gulpana or his cousin Doa, chosen for him as a wife by his family.
He decides to "test" his would-be brides and much of the film's two hours is taken up with long and extremely graphic sex scenes between the Horseman and his paramours.
A reverential hush reigns over the audience throughout, broken only by a few suspicious noises from certain rows, while at least half sneak out before the end.
The formula has made the Shama one of Peshawar's most successful cinemas at a time when many others have been forced to close.
The Islamisation that Pakistan witnessed in the 1980s persuaded many that the silver screen was a sinful depravation bad for the soul of a good Muslim.
The rise of videos, DVDs and the Internet accelerated the decline and now of around 15 cinemas in Peshawar 20 years ago, only seven remain.
Three of them show pornography, sometimes discreetly via clips hidden part way through mainstream action movies. The Shama, the best-known of the three, is regularly full, with tickets three or four times the price of normal films.
Key to its success is showing local-made pornography, which is much harder to find in Peshawar -- or on the Internet -- than Western adult films.
Coming to see Dostana
for a second time, Khaliq Khan, 30, said: "Like a lot of people here I prefer films with Pakistani girls. It's better, it seems more amateur, more real."
is certainly amateurish, with actors regularly turning to the camera quizzically, looking for direction for their next move.
The dialogue is dubbed in Pashto, the main language of the northwest, with an enthusiasm somewhat at odds with the bored, uninterested way the actors seem to be speaking in the original Punjabi.
But Janus Khan is quite happy. After the screening the labourer, 22, admitted he regularly came to the Shama "to enjoy myself, alone or with one or two friends".
"I'm not very pious but I'm not a rapist or unfaithful," he told AFP.
The Shama has provoked controversy in Pakistan, a constitutional Islamic republic with a very conservative attitude to sex and nudity.
Jamaat-e-Islami (JI), one of the country's leading religious political parties, has demanded the closure of the cinema.
But the cinema has powerful owners -- the Bilour family, one of the most influential in Peshawar and a pillar of the Pashtun nationalist ANP party.
Twice in the last 10 years Islamist activists including JI students have attacked the Shama, but both times the cinema has risen again.
Burned down in September 2012, it reopened a month later just in time for the Muslim festival of Eid al-Adha, which saw the Shama full.
How the cinema has avoided the attentions of the government censors, who cut even kissing from films, and the Taliban, who have destroyed countless supposedly "immoral" CD and DVD shops in recent years, is not clear.
In private, officials point to the wealth and influence of the Bilours -- always useful in a chaotic and corrupt country.
Back on the screen, Dostana draws to its conclusion with the indecisive Shah Sawar drowning his sorrows in alcohol.
Still unable to decide he summons the two women for a final menage-a-trois and in the film's climax at last resolves to marry them both.